Updated: 12/16/2017

Factor V Leiden

Topic
Review Topic
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Questions
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Snapshot
  • A 25-year-old Caucasian woman presents with her right calf larger than her left. She was recently started on oral contraceptive pills as birth control. She denies any long train rides or plane rides in the past few weeks. A dopper reveals a DVT in her right leg. She is started on LMWH. On further questioning, she reveals that she has had two spontaneous miscarriages. Her family history also includes multiple relatives with unprovoked DVTs.
Introduction

  • Hypercoagulable state/thrombophilia from mutated factor V
  • Genetics
    • factor V Leiden mutation
    • Mutation from Guanine to Adenine at nucleotide position 1691 (G1691A), which causes amino acid change from Arginine to Glutamine at amino acid position 506 (Arg506Gln)
    • incomplete autosomal dominant
  • Epidemiology
    • most common cause of inherited hypercoagulable states
    • most common in Caucasians
  • Pathogenesis
    • review of anticoagulation pathway
      • protein C (with protein S as a co-factor) inactivates factors V and VIII
    • mutated factor V lacks cleavage site for activated protein C
      • factor V remains active in coagulation pathway
      • defective anticoagulation
      • thrombosis
Presentation
  • Symptoms 
    • recurrent DVTs
    • DVTs beginning at a young age
    • PE
Evaluation
  • Diagnosis
    • activated protein C resistance assay (factor V Leiden specific functional assay)
    • if positive, confirm with DNA testing
  • Normal PT/PTT
Differential Diagnosis
  • Protein C/S deficiency
  • Malignancy
  • HIT
  • Antiphospholipid syndrome 
  • Antithrombin deficiency
Treatment
  • Antithrombolytics as needed with thrombosis
    • LMWH bridge to warfarin
Prognosis, Prevention, and Complications
  • Prognosis
    • mortality not affected
  • Prevention
    • avoid external causes of hypercoagulability
      • OCPs
      • hormone replacement therapy
  • Complications
    • miscarriage
    • thrombosis
 

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Questions (1)
Lab Values
Blood, Plasma, Serum Reference Range
ALT 8-20 U/L
Amylase, serum 25-125 U/L
AST 8-20 U/L
Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca2+) 8.4-10.2 mg/dL
Cholesterol, serum Rec: < 200 mg/dL
Cortisol, serum 0800 h: 5-23 μg/dL //1600 h:
3-15 μg/dL
2000 h: ≤ 50% of 0800 h
Creatine kinase, serum Male: 25-90 U/L
Female: 10-70 U/L
Creatinine, serum 0.6-1.2 mg/dL
Electrolytes, serum  
Sodium (Na+) 136-145 mEq/L
Chloride (Cl-) 95-105 mEq/L
Potassium (K+) 3.5-5.0 mEq/L
Bicarbonate (HCO3-) 22-28 mEq/L
Magnesium (Mg2+) 1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)  
24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL
Ferritin, serum Male: 15-200 ng/mL
Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL
Female: premenopause: 4-30 mIU/mL
midcycle peak: 10-90 mIU/mL
postmenopause: 40-250
pH 7.35-7.45
PCO2 33-45 mmHg
PO2 75-105 mmHg
Glucose, serum Fasting: 70-110 mg/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative stimuli: > 7ng/mL
Immunoglobulins, serum  
IgA 76-390 mg/dL
IgE 0-380 IU/mL
IgG 650-1500 mg/dL
IgM 40-345 mg/dL
Iron 50-170 μg/dL
Lactate dehydrogenase, serum 45-90 U/L
Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL
Female: follicular phase: 5-30 mIU/mL
midcycle: 75-150 mIU/mL
postmenopause 30-200 mIU/mL
Osmolality, serum 275-295 mOsmol/kd H2O
Parathyroid hormone, serume, N-terminal 230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L
Phosphorus (inorganic), serum 3.0-4.5 mg/dL
Prolactin, serum (hPRL) < 20 ng/mL
Proteins, serum  
Total (recumbent) 6.0-7.8 g/dL
Albumin 3.5-5.5 g/dL
Globulin 2.3-3.5 g/dL
Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL
Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h
Thyroxine (T4), serum 5-12 μg/dL
Triglycerides, serum 35-160 mg/dL
Triiodothyronine (T3), serum (RIA) 115-190 ng/dL
Triiodothyronine (T3) resin uptake 25%-35%
Urea nitrogen, serum 7-18 mg/dL
Uric acid, serum 3.0-8.2 mg/dL
Hematologic Reference Range
Bleeding time 2-7 minutes
Erythrocyte count Male: 4.3-5.9 million/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 12.0-16.0 g/dL
Hemoglobin, plasma 1-4 mg/dL
Leukocyte count and differential  
Leukocyte count 4,500-11,000/mm3
Segmented neutrophils 54%-62%
Bands 3%-5%
Eosinophils 1%-3%
Basophils 0%-0.75%
Lymphocytes 25%-33%
Monocytes 3%-7%
Mean corpuscular hemoglobin 25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration 31%-36% Hb/cell
Mean corpuscular volume 80-100 μm3
Partial thromboplastin time (activated) 25-40 seconds
Platelet count 150,000-400,000/mm3
Prothrombin time 11-15 seconds
Reticulocyte count 0.5%-1.5% of red cells
Thrombin time < 2 seconds deviation from control
Volume  
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 19-31 mL/kg
Cerebrospinal Fluid Reference Range
Cell count 0-5/mm3
Chloride 118-132 mEq/L
Gamma globulin 3%-12% total proteins
Glucose 40-70 mg/dL
Pressure 70-180 mm H2O
Proteins, total < 40 mg/dL
Sweat Reference Range
Chloride 0-35 mmol/L
Urine  
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 88-128 mL/min
Estriol, total (in pregnancy)  
30 wks 6-18 mg/24 h
35 wks 9-28 mg/24 h
40 wks 13-42 mg/24 h
17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 6-15 mg/24 h
Osmolality 50-1400 mOsmol/kg H2O
Oxalate 8-40 μg/mL
Potassium Varies with diet
Proteins, total < 150 mg/24 h
Sodium Varies with diet
Uric acid Varies with diet
Body Mass Index (BMI) Adult: 19-25 kg/m2
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(M1.HE.4752) A 35-year-old Caucasian female presents to the emergency room with unilateral leg swelling. She reports that she developed painful left-sided leg swelling and redness earlier in the day. She is otherwise healthy and takes no medications. She denies any recent prolonged travel. She experienced a similar episode affecting the opposite leg one year ago and was diagnosed with a thrombus in the right femoral vein. On examination, the left leg is erythematous and swollen. Passive dorsiflexion of the left ankle elicits pain in the left calf. Ultrasound of the leg reveals a thrombus in the left popliteal vein. A genetic workup reveals that she has an inherited condition. What is the most likely pathophysiology of this patient’s condition? Review Topic

QID: 108741
1

Elevated serum homocysteine

7%

(7/94)

2

Thrombin inhibitor deficiency

10%

(9/94)

3

Factor V inhibitor deficiency

54%

(51/94)

4

Auto-antibodies directed against phospholipids

6%

(6/94)

5

Resistance to clotting factor degradation

21%

(20/94)

M1

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PREFERRED RESPONSE 5
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